3-羟基-2-吡啶亚胺异构反应的机理

在RHF-6-31G,MP2/6-31G和MP2/6-31G水平上,对3-羟基-2-吡啶亚胺的气相、水分子作为催化剂的异构化反应进行了研究,结果表明,气象异构难于进行,水分子作为催化剂参与反应过程是目标反应所循的反应路径。     

α-Al2O3相变机理及制备工艺研究进展

α-Al2O3在耐火材料、电子材料等多个领域有着极其重要的应用.本文首先介绍了α-Al2O3在工业应用方面的评价指标和α-Al2O3的相变机理,接着分别从固相合成、液相合成、气相合成三个方面阐述了α-Al2O3制备的相关研究进展,对制备过程中影响α-Al2O3晶粒微观状态的若干因素,包括煅烧温度、矿化剂类型、pH值及预...     

两种高分子化锌卟啉络合物与特丁津相互作用的光谱性能研究

将苯基卟啉(PP)功能化的聚甲基丙烯酸缩水甘油酯(PGMA)即PP-PGMA和羟基苯基卟啉(HPP) 功能化的PGMA(HPP-PGMA)分别与锌离子发生络合反应,制得高分子化的苯基锌卟啉ZnPP-PGMA或羟苯基锌卟啉ZnHPP-PGMA。采用¹H-NMR对ZnPP-PGMA和ZnHPP-PGMA的化学结构进行了表征,用紫外-可见光谱法、荧光光谱法研究了其光谱性能。将ZnPP-PGMA或ZnHPP-PGMA与特丁津作用,研究特丁津对其光谱性能的影响。研究结果表明:高分子化的金属卟啉ZnPP-PGMA和ZnHPP-PGMA都具有强的光谱性能,相对于PP-PGMA和HPP-PGMA,其电子吸收光谱Soret吸收带红移,荧光发射峰蓝移。ZnPP-PGMA和ZnHPP-PGMA分别与特丁津作用后,ZnPP-PGMA的紫外光谱发生一定程度的红移,且ZnPP-PGMA和ZnHPP-PGMA发生明显的荧光猝灭现象。随着特丁津浓度的增大,ZnHPP-PGMA发生荧光猝灭的程度增大。     

过渡金属钴配合物催化Suzuki-Miyaura交叉偶联反应催化活性组分生成机理的理论研究

采用密度泛函理论(DFT)对过渡金属钴配合物催化Suzuki-Miyaura交叉偶联反应生成Co(Ⅰ)配合物(~(iPr)PNP)Co OR的反应机理进行了理论研究.结果表明,在反应过程中(~(iPr)PNP)配体中的一个膦配体从金属中心解离生成INT1',且三重态下的解离路径为优势反应路径;由INT1'生成Co(I)配合物(~(iPr)PNP)CoOR的解离反应路径中协同机理比分步机理更具优势;对底物ROH[R=Me,Et,~iPr,CH(Ph)Me]的R基团进行了调变,研究了生成(~(iPr)PNP)CoOR的解离路径的协同机理和分步机理中底物基团调变效应,当R=~iPr时反应的能垒最高.     

Coupling interaction between a single emitter and the propagating surface plasmon polaritons in a graphene microribbon waveguide

The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon （GMR） waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR, The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.     

Insights into the adsorption of water and oxygen on the cubic CsPbBr3 surfaces: A first-principles study

The degradation mechanism of the all-inorganic perovskite solar cells in the ambient environment remains unclear. In this paper, water and oxygen molecule adsorptions on the all-inorganic perovskite (CsPbBr₃) surface are studied by density-functional theory calculations. In terms of the adsorption energy, the water molecules are more susceptible than the oxygen molecules to be adsorbed on the CsPbBr₃ surface. The water molecules can be adsorbed on both the CsBr- and PbBr-terminated surfaces, but the oxygen molecules tend to be selectively adsorbed on the CsBr-terminated surface instead of the PbBr-terminated one due to the significant adsorption energy difference. While the adsorbed water molecules only contribute deep states, the oxygen molecules introduce interfacial states inside the bandgap of the perovskite, which would significantly impact the chemical and transport properties of the perovskite. Therefore, special attention should be paid to reduce the oxygen concentration in the environment during the device fabrication process so as to improve the stability and performance of the CsPbBr₃-based devices.     

双核过渡金属络合物引发氮分子活化研究

将自然界资源丰富但化学性质上极其惰性的氮气分子在温和条件下转化为氨及其他含氮化合物,具有非常重要的意义。过渡金属络合物引发氮分子的活化及官能化已成为现代工业固氮的一大研究热点。本文回顾了氮分子与双核过渡金属络合物结合的键型模式,总结了影响氮分子活化的诸多因素如配体调变效应、金属调变效应等,对双核过渡金属络合物引发的双氮裂解、双氮官能化及CO/CO2协助双氮活化官能化等反应的实验与理论研究现状和进展进行了简要综述,并对未来过渡金属络合物在氮分子固定的应用发展作了展望。     

离子液体-水介质中离子液体负载TEMPO催化选择氧化合成脂肪醇羟基芳香醛和酮

由于脂肪醇羟基和苄醇羟基具有相同的氧化反应活性,所以当分子内同时含有脂肪醇羟基和苄醇羟基时,很难选择氧化苄醇羟基合成含脂肪醇羟基的芳香醛或酮。本文报道了在离子液体-水介质中,NCS/NaBr/IL-TEMPO（离子液体负载TEMPO）催化氧化合成含有脂肪醇羟基的芳香醛、酮的方法,反应条件温和,选择性好,收率高,且离子液体和催化剂可以循环使用。     

钢化玻璃冲击波毁伤效应测试结果分析

为研究爆炸冲击波对钢化玻璃的毁伤阈值,开展了钢化玻璃冲击波毁伤效应实验。对每一发实验进行了爆炸参数测试,获得了冲击波超压随时间变化历程的实验数据。通过对实验数据的处理与分析,得到了爆炸冲击波基本参数,包括正反射超压、冲击波到时、正压作用时间、正反射冲量、负反射超压、负压作用时间和负反射冲量等。将实验结果与CONWEP计算结果进行了比较,比较结果表明二者误差很小,证明冲击波测试结果准确可靠。对冲击波正负反射参数进行了比较,结果表明冲击波正反射参数明显高于冲击波负反射参数。